With the wide usage of touch screens, various structures of touch electrodes have been developed. These structures of touch electrodes can be installed at different positions of a display device to recognize touch operations by a user. However, conventionally the touch electrodes are manufactured independently from the display devices. Such low level of integration between the touch electrodes and the display devices not only makes the manufacturing process of a touch screen complicated, but also causes the touch electrodes to occupy a large space in a display device.